A general boycott plays into the hands of Israel's hard-right leaders. Instead, we should punish firms and institutions that operate in the Occupied Territories.

If the aim was to hit Israel where it hurts, Stephen Hawking’s withdrawal from the Israeli Presidential Conference couldn’t have been better planned. Hawking had accepted an invitation to the gathering of world leaders and scholars in June, but announced yesterday he was dropping out in solidarity with Palestinian academics who have called for a boycott of Israel. Israel’s self-image as a full member of the community of nations rests to a large extent on its global prominence in science and technology. This move, by the world’s most famous scientist, punches a hole in that cherished idea, reminding Israel of its other identity: that of a semi-pariah state, synonymous with occupation and war.

So why, as a fervent supporter of Palestinian rights, can’t I bring myself to support Hawking’s decision? In a decade-and-a-half of visits to Israel/Palestine, I have seen at first-hand the effects of Israel’s cruel occupation. I have heard West Bank residents describe the despair caused by Israel's system of closures, roadblocks and curfews, and seen the degrading conditions of refugee camps like Dheisheh and Jenin. I have stood alongside Palestinians protesting the loss of their lands to settlements and the 'separation fence'. And, writing about the conflict, I have likened Israel to a junkie with a "deadly addiction" to Palestinian land.

Nor is my opposition to Hawking’s move based on the usual argument trotted out against the so-called Boycott, Divestment and Sanctions (BDS) movement. Partisans of Israel often charge BDS with inconsistency, claiming it’s hypocritical to single out Israel and not other countries who abuse human rights. But this won’t wash. When it comes to moral acts, the question isn’t whether we are consistent but whether we have a chance of achieving some good. When activists led a boycott of South Africa during the apartheid years, they didn’t wait until their movement could boast a consistent platform on every conceivable issue. And the clear message they sent the South African regime – that its practices were intolerable in the modern world – helped bring about its downfall.

The problem with the BDS campaign is that the message it sends Israel is anything but clear – and, as a result, it risks being counterproductive. In his letter to the conference’s organisers, Hawking wrote about his concerns about "prospects for a peace settlement", saying that "the policy of the present Israeli government is likely to lead to disaster". But Israel’s supporters claim that the BDS movement has little to do with the occupation, peace, and government policy, and is instead intended to bring into question the Jewish state’s right to exist.

It’s true that Israel’s supporters throw the word 'delegitimisation' around to portray fair-minded criticism of Israel as invidious and sinister. But when it comes to BDS, the fact is that they have a point. The BDS movement doesn’t have a single leadership with stated goals, but most of the biggest groups within it make little secret of their preferred outcome to the conflict. Instead of a two-state solution, they support a single, Palestinian-majority state that would mean the end of Israel’s existence. Don’t take my word for it. Norman Finkelstein, the heroic pro-Palestinian author and activist, recently launched a blistering attack on the BDS movement, telling an interviewer: "[The Israelis] say 'They’re not talking about rights. They want to destroy Israel.' And in fact, I think they’re right. . . . There’s a large segment of the movement that wants to eliminate Israel."

Stephen Hawking is a brave and principled man, and there’s no doubt his gesture was intended to send Israel a signal about the need for peace and an end to its oppression of Palestinians. But, in doing so, he has added his considerable weight to a movement whose aims are in many ways the opposite of his message of peace and reconciliation. It’s significant that the website of the Palestine Solidarity Campaign, one of the biggest UK supporters of BDS, reproduced Hawking’s letter of withdrawal – but clipped the part which referred to a "peace settlement".

But how important is all this? If moves like Hawking’s help Israel understand that its policies will not be tolerated by the rest of the world, does it matter if they were orchestrated by a medley of groups harbouring a fantastical goal that has no chance of being realised? The most important thing, surely, is to bring pressure on Israel to change course, and end the forty-six-year-old occupation.

But here’s the thing: whatever the intentions of figures like Hawking, what Israel hears from BDS is the voices questioning its right to exist. This plays into the narrative of its hard-right leaders, who tell their people: "The world will never accept us, and we must rely on our own strength to survive. That is why we must never compromise or show vulnerability." It’s for this reason that Noam Chomsky – hardly a Zionist stooge – has said that a general boycott of Israel is "a gift to Israeli hardliners and their American supporters".

In this way, we can send Israel a clear and bold message. We can say: "We support your right to live in peace and security. But we reject the occupation of a single inch of Palestinian soil, the demolition of single Palestinian home, the spilling of a single drop of innocent blood."

This isn’t about pulling our punches, or sending Israel a softer message. It’s about refusing to give its leaders a reason not to hear us.